It has just emerged that last week, in a secret decision made without any public announcement, President Goodluck Jonathan of Nigeria signed into law one of the world's most draconian anti-gay statutes. Whatever the motive for the hush-up, it didn't hold. The world now knows.

Can you imagine what it would be like to wake up one morning to discover that it was suddenly illegal for you to be you? That the law said because you had blue eyes, or were short or because you wrote with your left hand you could go to jail. The character I'm best known for - Captain Jack in Torchwood - spends his life fighting every kind of threat to humanity you could think of. That's all fantasy, of course, but this is real. People are being killed and many, many more live in daily fear for their lives. And the threat comes from something that is much harder to fight than fictional aliens - homophobia based on prejudice, hatred and ignorance.